table: PIT on NameTree

ref# 1194

Change-Id: I32f103374885445725fc5deeebda60b1b1e54c2f
tests: resetGlobalIoService for every test

All tests must use BaseFixture or a fixture derived from it to get this feature.

This commit also fixes a few warnings in tests/mgmt, and moves test cases into nfd::tests namespace.

refs #1290

Change-Id: I891441a5abce170e35648d463f7157b18429f79f
face: Ignoring fireware interfaces (fw*) in EthernetChannelFactory

Change-Id: Ibfb512ce1229e74eee4c66efd87d6dc4a18c057e
face: remove awkward Face::setLocal, use a constructor argument instead.

Change-Id: Ic366ecdc83c5771138ff584ffb944a4e17300eb1
build: Allow option to force compilation with unix sockets enable

This feature will be useful for cross-compilation, when it is impossible
to execute the compiled code on the host platform.

Change-Id: Ie3d7a1ce5fc5dd5e04aa1bb77efa2c4c6755e566